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[S390] replace diag10() with diag10_range() function 

Currently the diag10() function can only release one page. For exploiters
that have to call diag10 on a contiguous memory region this is suboptimal.
This patch replaces the diag10() function with diag10_range() that is
able to release multiple pages. In addition to that the new function now
allows to release memory with addresses higher than 2047 MiB. This was
due to a restriction of the diagnose implementation under z/VM prior to
release 5.2.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Michael Holzheu 2011-05-10 17:13:41 +02:00 committed by Martin Schwidefsky
parent 91d378088b
commit 83ace2701b
3 changed files with 16 additions and 24 deletions
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17
arch/s390/include/asm/diag.h
View File

@ -9,9 +9,22 @@
#define _ASM_S390_DIAG_H
/*
* Diagnose 10: Release pages
* Diagnose 10: Release page range
*/
extern void diag10(unsigned long addr);
static inline void diag10_range(unsigned long start_pfn, unsigned long num_pfn)
{
unsigned long start_addr, end_addr;
start_addr = start_pfn << PAGE_SHIFT;
end_addr = (start_pfn + num_pfn - 1) << PAGE_SHIFT;
asm volatile(
"0: diag %0,%1,0x10\n"
"1:\n"
EX_TABLE(0b, 1b)
EX_TABLE(1b, 1b)
: : "a" (start_addr), "a" (end_addr));
}
/*
* Diagnose 14: Input spool file manipulation

21
arch/s390/kernel/diag.c
View File

@ -8,27 +8,6 @@
#include <linux/module.h>
#include <asm/diag.h>
/*
* Diagnose 10: Release pages
*/
void diag10(unsigned long addr)
{
if (addr >= 0x7ff00000)
return;
asm volatile(
#ifdef CONFIG_64BIT
" sam31\n"
" diag %0,%0,0x10\n"
"0: sam64\n"
#else
" diag %0,%0,0x10\n"
"0:\n"
#endif
EX_TABLE(0b, 0b)
: : "a" (addr));
}
EXPORT_SYMBOL(diag10);
/*
* Diagnose 14: Input spool file manipulation
*/

2
arch/s390/mm/cmm.c
View File

@ -91,7 +91,7 @@ static long cmm_alloc_pages(long nr, long *counter,
} else
free_page((unsigned long) npa);
}
diag10(addr);
diag10_range(addr >> PAGE_SHIFT, 1);
pa->pages[pa->index++] = addr;
(*counter)++;
spin_unlock(&cmm_lock);